This headline comes to you courtesy of the Wayback Machine from January 3, 1961. It’s for all of us who mistakenly believe that Three Mile Island was the most serious nuclear accident in U.S. history. Not by a long shot. The meltdown at the Stationary Low-Power Reactor Number One (SL-1) in south-central Idaho is to date the only fatal meltdown in U.S. history.

The SL-1 before it blew up. The nuclear reactor is in the cylindrical structure. Source: Argonne National Laboratory.

The Argonne Low Power Reactor (ALPR) was designed and built in 1958 by Argonne National Laboratory at a military test facility about 40 miles from Idaho Falls. Shortly after it became operational, it was handed over to the U.S. Army and renamed SL-1 in accordance with Army nomenclature. Its purpose was to test the feasibility of building small-capacity nuclear power plants in the Arctic for military radar stations that monitored Soviet air activities. The idea was to generate 200 kilowatts—just enough for an average-sized house. The whole kit ‘n caboodle was designed to be portable.

On December 23, 1960, SL-1 was shut down for maintenance and updates. The process of restarting the reactor began on January 3, 1961. A three-man crew on the night shift worked through the laborious, step-by-step process, documenting everything in a log. A crucial part of this process involved withdrawing a central control rod from the reactor core a distance of four inches in order to reconnect it to its automatic control mechanism.

For some reason, however, the operator withdrew the rod about 26 inches. The reactor immediately went critical. Water vaporized and a massive steam explosion lifted the entire reactor nine feet straight into the air. The force of the explosion killed the operator, John Byrnes, instantly. Richard Legg, the shift supervisor, who had been standing on top of the reactor, was impaled into the ceiling of the structure by flying debris. He also died instantly. Richard McKinley, a trainee who had been observing the procedure from a few feet away, died of trauma wounds shortly afterwards. It was the country’s first nuclear meltdown.

Had the men not succumbed to physical injuries, they would have died from radiation exposure within a day. All three were buried in lead-lined coffins inserted into metal vaults and covered with concrete. Some body parts were removed and buried separately as highly radioactive waste. The good news, if such a thing was possible, was that the amount of radiation released into the atmosphere from explosion was considered negligible and had a half life of just a few days. Clean-up took about 18 months.

The accident has mostly been relegated to the dustbin of history, but when it is remembered it is usually in conjunction with the layers of urban legend that have wrapped themselves around the facts of the story. Rumors of a love triangle between Legg, Byrnes, and Legg’s wife gave rise to the suggestion that the accident was actually a murder-suicide. This seems a fanciful but somewhat irresistible plot development for those who lose themselves in the Wayback Machine, where speculation is a more precious currency than fact.

No doubt, the accident was certainly avoidable and probably at least partially caused by poor communication and workplace tension. According Todd Tucker, author of Atomic America, the Legg and Byrnes couldn’t stand each other and “had even come to drunken blows at a sleazy bachelor party the year before.” Byrnes had faced disciplinary action in the Army and his career was in jeopardy. Professionally, Legg had leapfrogged over Byrnes and was now his supervisor. Byrnes was full of resentment. To make matters worse, just two hours before the accident occurred, Byrnes’s wife had called him at SL-1 to say she wanted a divorce. She later allegedly told investigators that her husband warned her that an accident was possible and she had tried and failed to reach him again that same evening at SL-1.

So as Byrnes was on top of the reactor, charged with lifting the 84 lb. central control rod not more than four inches out of the reactor, he was probably not in a good mood and probably not focused solely on the task at hand. Furthermore, the control rod was in ill-repair and frequently needed to be jiggled with a heavy wrench. It had a history of being difficult to maneuver. In a matter of milliseconds, according to Tucker,

The shield plug was ejected from the core at eighty-five feet per second, entered Legg’s body through his groin, exited near his shoulder, and propelled him straight up to the ceiling where he dangled for six days. The impaled body was so radioactive that it took engineers that long to design a safe way to remove it. When they did finally bring Legg down, they were shocked to see that despite the time that had passed, the body was perfectly preserved. It was so radioactive that the sterilized flesh had no decayed.

Rescuers initially thought they were responding to another false alarm, which would have been the third one that day. Instead, they found an eerily silent building even as the needles on their radiometers went berserk. They followed a series of protocols that allowed full-suited responders only 60 seconds to search and rescue the victims from the scene. In all, 790 people were exposed to harmful radiation during the rescue and clean up operations; 32 of them received certificates of heroism from the Atomic Energy Commission.

The full dismantling of the reactor and site clean up took 18 months. All debris and contaminated soil and gravel was buried about 1,600 feet from the original site of the reactor. It is continually monitored for radiation; in 2000 the site was capped with an added layer of rocks.

The incident was investigated thoroughly and resulted in many improvements in subsequent nuclear reactors—enough that a similar accident has never again taken place. Most importantly, it is no longer possible to cause a nuclear meltdown by having one operator yank out a control rod at whim. Thank goodness.

The event, while perhaps not part of the American consciousness, like the Bay of Pigs invasion that happened just several months later, has resulted in a number of insightful analyses that trace the development of nuclear power and safety in the United States.

The Atomic Energy Commission even produced a documentary that includes re-enactments of the disaster. It’s quite a feat of filmmaking, complete with a soundtrack that’s right out of a Hitchcock suspense movie. Here’s the link.

Additionally, independent filmmakers C. Larry Roberts and Diane Orr released SL-1 in 1983. Janet Maslin reviewed the film in the New York Times, noting that “parts of the bodies of the three dead men had to be removed and buried separately, because they were ‘hot’ enough to be considered high-level nuclear waste. This surgical work had to be performed using knives and hacksaws fastened to the ends of long poles.”

The damaged core of SL-1. Source: Idaho National Engineering and Environmental Laboratory.

Idaho Falls: The Untold Story of America’s First Nuclear Accident by William McKeown was published in 2003. McKeown explores how the murder-suicide angle was given credence many years after the fact, as anti-nuclear activists hunted for proof of sabotage as a reason to close down the country’s reactors. McKeown suggest that “Byrnes was an inquisitive kid and might have yanked up the rod just to see what would happen, never imagining the consequences. The wife of another sergeant at the reactor thought that young Jack Byrnes was an impulsive guy: he drove too fast, lived too hard, did things without thinking. She though it was possible that he pulled the rod on a whim. But she also speculated that, given his personal problems, he could have done it deliberately to take his own life.”

Needless to say, the accident put the kibosh on the Army’s quest to build portable nuclear power plants. Soon, the Air Force also abandoned its plans for a nuclear-powered aircraft. Only the Navy remained in the nuclear game, having already engineered a nuclear-powered submarine that had passed beneath the North Pole the year before. Nuclear submarines have a notorious track record of disasters all their own, but that’s a story for another time.

Continuing the Discussion

[…] It's for all of us who mistakenly believe that Three Mile Island was the most serious nuclear accident in U.S. history. Not by a long shot. The meltdown at the Stationary Low-Power Reactor Number One (SL-1) in south-central … Article by radioactive meltdown – Google Blog Search. Read entire story here. […]

[…] It's for all of us who mistakenly believe that Three Mile Island was the most serious nuclear accident in U.S. history. Not by a long shot. The meltdown at the Stationary Low-Power Reactor Number One (SL-1) in south-central … Article by radioactive meltdown – Google Blog Search. Read entire story here. […]